Did Late Practice Fix Or Create Problems At MIS?

New tires were brought in Saturday in an effort to solve blistering problems at Michigan. (RacinToday/HHP photo by Alan Marler)

By Jim Pedley | Managing Editor
RacinToday.com

Scheduling an extra practice Saturday so that Sprint Cup teams could test new, harder tires on Michigan International Speedway’s new, ultra-high speed pavement seemed like a good idea – at the time. However, it proved costly.

The harder left-side tires brought in did slow the cars, but the stress placed on the engines took a toll as a couple cars – including that of five-time champion Jimmie Johnson – had to make changes.

Here is what a couple of drivers had to say about the late Saturday afternoon practice:

Marcos Ambrose, driver of the pole-sitting No. 9 Richard Petty Motorsports Ford Fusion, said, “Well, we were out there trying to save miles on the engine, so we never really busted off a good run. The tire is very different. It hasn’t got much grip. You are loose in, shake in the middle and then on the gas spin yourself out. It feels unbalanced and a little bit wobbly and you don’t want to be wobbly at 200 mph. You want to feel like the car is underneath you. I think we did enough stuff during practice to get a feel for what we need. We will make some adjustments tonight and get ready for tomorrow.”

Greg Biffle, driver of the No. 16 Roush Fenway Racing Ford Fusion, said, “The tires are really hard, you can tell. It is giving up a lot of grip. It is kind of funny, you can hear the tires squealing when you first go out, before it builds temperature, you can feel it sliding on the race track. It slows the cars down and as it

builds heat it actually starts to gain some of that grip back. I think the biggest thing with this tire that I remember is the first three laps off of the yellow as the hardest racing around other cars. The thing will just take off on you. That is the biggest thing we need to stay cautious of. After you get four or five laps in a run I think it will race pretty normal.

“It kind of threw us for a loop – the engine guys mostly. They have set amount of miles we can put on the engines and we are a little over this weekend. We are on the throttle so much around here that we are a little concerned with the engine package anyway. This is a little added blood pressure for them all day tomorrow.”

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Trivia time

Which driver in today’s field has the most top-10 finishes at Michigan?

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Fast facts

The track: Michigan International Speedway

Configuration: 2-mile tri-oval

Banking in corners: 18 degrees

Grandstand seating capacity: 85,000

The race: The Michigan 400

The distance: 400 miles (200 laps)

Last year’s pole-sitter: Kurt Busch

Last year’s race-winner: Denny Hamlin

First race: Motor State 500 (1969)

First pole-sitter: Donnie Allison

First winner: Cale Yarborough in a Mercury

Most wins at MIS: 9, by David Pearson

Most poles: 10, by David Pearson

Most top-fives: 21, by Cale Yarborough

Narrowest margin of victory: .085 seconds (2001)

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The keys

The keys to today’s race at MIS come from Howard Comstock of SRT Motorsports Engineering:

Tires: “Obviously the biggest problem is going to be the change of left-side tires. After all of the tire testing we did, all of the testing that we did on Thursday and all of the practice that we had on Friday, the left-side tire is still a problem. The left-side tire won’t give up the heat and we saw several instances of blistering on the left-sides. It’s not unprecedented but NASCAR has decided that we’re going to change the left-side tires not for qualifying but for the race. An extra practice session has been scheduled after the Nationwide race. It’s disappointing that after nine hours of track time, we have to change the left-side tire and we’ll only get an hour to adapt to it. Figuring out that new left-side tire is going to be a big key.

“The fact that we’ve spent so much time trying to adapt to the tires that were provided and now there’s going to be a different tire, that’s a big change. We have computer programs that design suspensions to deal with specific tires and their characteristics. We model the tires, we study the tires, we think we understand the grip level of the tires and all of the suspension simulation is built around the tires. Now to change the left-sides for the race, it’s a big deal. It’s not an insurmountable problem but it’s a big deal.”

Engine Durability: “Obviously we’ve changed the gearing to bring the RPM back down even with the advance speeds. The thing that gets the engine here is the fact that you stay on the throttle for so long, the only time the engine gets to breathe is when you lift off the throttle. With so much on-throttle time because of the grip in the corners, that’s the problem that teams have to consider with the engine. We’ve been able to control the RPM levels by changing the gearing but the amount of on-throttle time is going to be a problems for durability.”

Fuel Economy: “Fuel economy is always an issue here at Michigan. It’s always a challenge to figure it out. It always seems to come down to a fuel economy race at the end. At the speeds that we’re seeing, we’re making more power. The throttle is open more all the way around the racetrack which means we’re using more fuel. We’ve got fuel injection this year, so a combination of faster speeds, more wide-open throttle time, fuel injection, that’s a lot of variables to throw at everybody. We’ve just got to conquer all those issues.

“It’s going to be a test of calculating fuel economy because we’ve never run speeds like this before. We’ve certainly never run speeds like this with the fuel injection. How is that going to turn out? I think the teams will have to be conservative early in the race and make sure you don’t run out of fuel. If you ran out of fuel on the backstretch, you could coast to the pits but you’ll lose a lap in the process. You can’t afford that. I’ve already heard teams talking about backing up their first pit stop a lot. I would say that you’ll see pit stops in the 30-40 lap range.”

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Speed is relative

The Cup cars spent a lot of time at 200-plus mph at Michigan this week. Pretty fast, eh Tony Stewart?

“No, not when you ran 247 miles per hour in an Indy car at Indy in rookie orientation,” the three-time champion said. “We’ve been around that number at Daytona and Talladega it’s just kind of cool to do it with an open motor at 200 miles per hour.

“I don’t know why. I think it’s kind of getting to the speed where we were when we were running Indy cars a little bit. We are running 217 at the end of the straight-a-way here so your starting to get in speeds that I was used to running in the IRL (Indy Racing League) but the cars feel comfortable enough that they have got a stable enough platform that it kind of feels that way. It seems like the longer we are doing it and the longer we are running these speeds the slower it is starting to feel to us.”

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Good and bad

Roush Fenway Racing driver Carl Edwards is having a tough year. The man who lost last year’s championship on a tie-breaker is winless and 11th in points. He is also low driver on the RFR totem pole as teammates Matt Kenseth and Greg Biffle are first and third in points pre-race at MIS.

Edwards was asked about his year. He said: “They are two different things – performance and results – you can run very well and have a bad result because of something that goes on. This is a test of man and machine and you have other competitors out there. A lot of circumstances can happen that can cause you to have a bad day. I think our performance, I would say we deserve to be about fifth in the points and we are 11th.

“I don’t think we deserve to be leading it, even if we had the luck that we had last year, I think we would be top-five in points but I wouldn’t say we would be dominating. I think the performance is not as good as it needs to be but it isn’t far off. If we get a little luck, find a little speed, we will be just fine. We just have to make the Chase obviously to have a shot at anything for us this season. To get a shot at that championship we gotta make the Chase.”

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Trivia answer

Mark Martin has 31 top-10 finishes in 52 starts at MIS.

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Up next

The series goes road racing for the first time in 2012 as it heads to Sonoma. Last year’s race was won by Kurt Busch. Joey Logano was the pole-sitter.